FastMM will raise an exception when DataTarget is assigned on a IWBSButton and destruction of the form.
This is a work around I have found to ensure it is set to NIL
destructor TIWBSButton.Destroy;
var
LDataTarget: Pointer;
begin
try
if Assigned(FDataTarget) then
begin
LDataTarget := @FDataTarget;
if LDataTarget <> nil then
begin
try
Pointer(FDataTarget) := nil;
except
end;
end;
end;
finally
inherited;
end;
end;
To replicate enabled FastMM4 debug options on the IWBSDemo start demo and then exit.
To fix without using this above, edit Unit2 and add a FormDestroy event
IWBSButton49.DataTarget := nil;